Table 1.

Definitions of major and minor flaws for this SR

	Experimental studies (clinical trial or community trial)	Longitudinal Observation (cohort study or observational study)	Cross-sectional
Study population: Major	• No Control • Sample size inadequate for power (n < 20 per group) • Non-random allocation or randomisation not described	• Not representative of the population of interest. In relation to age, gender AND • Confounders not accounted for • No description of sample	• Not representative of the population of interest. In relation to age, gender AND • Confounders not accounted for. • No description of sample
Minor	• Confounders not completely accounted for • Omission of detail about confounders.	• Not representative of the population of interest. In relation to age, gender • Omission of detail about confounders • Non-random sampling • Sample size inadequate for power (n < 10 per variable) or not described (if study n < 500)	• Not representative of the population of interest. In relation to age, gender • Confounders not accounted for • Non-random sampling • Sample size inadequate for power (n < 10 per variable) or not described (if study n < 500)
Intervention/ exposure: Major	• No description of the PA or SS component of the intervention • No measurement of intervention strength or exposure • Intervention <12 weeks	• No measurement of exposure • Poor or no face validity of measurement of exposure	• No measurement of exposure • Poor or no face validity of measurement of exposure
Minor	• No blinding	• No validity of measurement PA or SS exposure mentioned	• No validity of measurement PA or SS exposure mentioned
Outcome: Major	• Poor face validity of measurement of outcome	• Poor or no face validity of measurement of exposure	• Poor or no face validity of measurement of PA or SS outcome
Minor	• No validity of PA or SS outcome measure mentioned	• No validity of PA or SS outcome measure mentioned	• No validity of PA or SS outcome measure mentioned
Follow-up: Major	• High drop-out (>20%) (from pre to post- test measurement)	• High drop-out (>20%) (from pre to post-test measurement)	• NA
Minor	• High drop out in long term follow up (post intervention) • No long term follow up	• High drop out in long term follow up (post intervention) • No long term follow up	• NA